无机材料学报

• 研究论文 • 上一篇    下一篇

低热固相反应法在多元金属复合氧化物合成中的应用—锂离子电池正极材料r-LiMnO2的合成、结构及电化学性能研究

唐新村1; 何莉萍1; 陈宗璋1; 贾殿赠2   

  1. 1. 湖南大学化学化工学院, 长沙 410082; 2. 新疆大学应用化学研究所, 乌鲁木齐 820046
  • 收稿日期:2002-01-11 修回日期:2002-03-04 出版日期:2003-03-20 网络出版日期:2003-03-20

Application of the Low-heating Solid-state Reaction Method in Preparation of Multi-metal Oxides Composite -Synthesis, Structure and Electrochemical Properties of Rhombohedral LiMnO2 Cathode Material for Lithium-ion Batteries

TANG Xin-Cun1; HE Li-Ping1; CHEN Zong-Zhang1; JIA Dian-Zeng2   

  1. 1.College of Chemistry and Chemical Engineering; Hunan University; Changsha 410082; China; 2.Institute of Applied Chemistry; Xinjiang University; Wulumuqi 820046; China
  • Received:2002-01-11 Revised:2002-03-04 Published:2003-03-20 Online:2003-03-20

摘要: 以氢氧化锂,醋酸锰和草酸为原料,采用低热固相反应法于350~700℃下直接通过热处理制备了锂离子电池正极材料r-LiMnO2粉体样品.X射线衍射分析表明,采用该法得到的样品与LiCoO2具有类似的晶型.由于Mn3+的Jahn-Teller效应使r-LiMnO2与同样方法合成的LiCoO2及LiCo0.8Ni0.2O2相比,晶胞形状变得更加扁平,晶胞体积增大.选区电子衍射研究表明高于600℃焙烧温度所得的r-LiMnO2样品中含立方尖晶石结构杂质相. 2.5~4.3V之间的充放电测试结果表明,样品的充放电容量随焙烧温度的升高而增大,但高于600℃的样品具有3V和4V两个充放电平台,而350~500℃的样品只有一个3V充放电平台,并且循环过程中结构非常稳定.

关键词: 锂离子电池, 低热固相反应法, r-LiMnO2正极材料

Abstract: LiMnO2 compounds with rhombohedral structure were prepared by the low-heating solid-state reaction method at the
temperature range of 350~700℃. The powder X-ray diffraction technique was applied to investigate the structures of the obtained samples.
XRD result shows that the structures of these samples are the same as that of LiCoO2. Compared with LiCoO2 and LiCo0.8Ni0.2O2 prepared by
the same method, the lattice parameter of r-LiMnO2, c/a, is relatively smaller due to the Jahn-Teller deformation. Selected-area electron diffraction
and XRD results indicate the existence of the cubic spinel impurities in the r-LiMnO2 samples sintered at 600℃ and 700℃. The tests of
charge/discharge show that the samples prepared above 600℃ have two voltage plateaus of 3V and 4V, of which the plateau at 4V is related to the
cubic spinel impurities. Whereas, the samples obtained below 500℃ present only one plateau of 3V. Especially, the sample obtained at 500℃
exhibits good structural stability in lithium-ion intercalation/deintercalation processes.

Key words: rhombohedral LiMnO2, Low-heating solid-state reaction, lithium-ion batteries

中图分类号: